Introduction to Microbiology Brief History of Microbiology 1st Course Lec.#1 06. Dec. 2020
Dr. Kawakib I. Al-Zubaidy
1 What is Microbiology? Microbiology is the science that deals with the study of biological organisms that are too small to be seen with the naked eye (without using microscope).in order to not only determine how they live in their environment, but also how they impact their respective surroundings and thus other organisms around them (human beings, animals, etc).
Microorganisms or microbes- these microscopic organisms Commonly called “germs”. Bacteria, Archaea, Fungi, Protozoans, Algae, Viruses Some organisms are large though – Helminths – worms Multicellular animal parasites – Helminths * Not all cause disease and many more are useful or essential for human life
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3 4 Bacteria Fungi
Protozoans Giardia Ameba
5 Viruses Bacteriophage Avian Flu
Helminth ; Tapeworm
6 Why Do We Study Microorganisms?
We study microbiology because bacteria, viruses and fungi are the leading cause of death in the history of mankind. Some Microorganisms Benefit Man: Many microorganisms are involved in the production of food or are directly edible. The presence of bacteria (normal flora) in our bodies inhibits the growth of potentially pathogenic bacteria helping to keep us healthy. Modern biotechnology is often associated with the use of genetically altered microorganisms such as E. coli or yeast for the production of substances like synthetic insulin or antibiotics.
7 Why Do We Study Microorganisms?
Biotechnological advances in agriculture also require the help of microorganisms to form Transgenic Plant with increased yield, reduced vulnerability to environmental and pathogenic stresses, and improved taste. Microbes are involved in cycling vital elements such as carbon and nitrogen. In aquatic ecosystems microbes are even used to digest oil from oil spills.
8 CONTRIBUTIONS OF RENOWNED SCIENTISTS IN MICROBIOLOGY ROBERT HOOKE
9 ANTON VON LEEUWENHOEK “Father of Bacteriology” He was the first to observe bacteria and protozoa. Leeuwenhoek made microscopes consisting of a single high-quality lens of very short focal length. In 1674 he observed protozoa and bacteria and named them as “animalcules”, he was able to isolate from different sources, such as rainwater, pond and well water, and the human mouth and intestine.
10 Spontaneous Generation (Abiogenesis)
From earliest times, people had believed and supported spontaneous generation (abiogenesis); states that living organisms could develop from nonliving matter. Many supported this theory. It was Louis Pasteur who disproved the theory.
11 Francesco Redi (1668) – Strong opponent of spontaneous generation. He demonstrated that maggots appear on decaying meat only when flies are able to lay eggs on the meat. John Needham (1745) – claimed that microorganisms could arise spontaneously from heated nutrient broth. Lazzaro Spallanzani (1765) – repeated Needhams experiments and suggested that Needham's results were due to microorganisms in the air entering the broth.
Louis Pasteur (1822-1895) – Pasteur's experiments on swan shaped necks resolved the controversy of spontaneous generation. His discoveries led to the development of aseptic techniques used in the laboratory and medical procedure to prevent contamination by microorganisms that are in the air.
12 Francesco Redi
13 14 15 16 The Golden Age of Microbiology
• 1857-1914 • Beginning with Pasteur’s work, discoveries included the relationship between microbes , Fermentation and Pasteurization
17 18 19 20 Germ Theory of Disease
• Germ theory of disease states that certain diseases are caused by the invasion of the body by microorganisms, organisms too small to be seen except through a microscope.
21 Germ Theory of Disease 1876 - Robert Koch provided proof that a bacterium causes anthrax using experimental steps now called the Koch’s Postulates
Koch’s Postulates The microbe must always be present in every case of the disease It must be isolated in pure culture on artificial media When inoculated into healthy animal host it should produce the same disease It must be isolated from the diseased animal again
22 23 24 VIROLOGY Martinus Beijerinck (1851-1931 characterized viruses as pathogenic molecules that could take over a host cells mechanisms for their own use. Knoll and Ruska- Viruses were first observed with an Electron Microscope in 1939 James Watson and Francis Crick (1953) -determined the structure of DNA
25 The Birth of Modern Chemotherapy
• 1928: Alexander Fleming discovered the first antibiotic. • He observed that Penicillium fungus made an antibiotic, penicillin, that killed S. aureus. • 1940s: Penicillin was tested clinically and mass produced.
Similar26 to Figure 1.5